Indonesia is determined to assert its exclusive right to a corner of the South China Sea (Vietnam's East Sea) where there has been a run of skirmishes between Indonesian navy ships and Chinese vessels, the vice-president said on Monday.

A Chinese observation ship shadowed the powerful U.S. aircraft carrier, John C. Stennis, in the Western Pacific on Wednesday, a Japanese official said, joining warships from Japan and India in drills close to waters Beijing considers its backyard.

The ship's capacity was 28 but it was carrying 56 people, including crew members. Passengers gathered on one side of the ship to enjoy the view of the Han River at night caused the ship to list and eventually go down.